Formation of Blueschist and Greenschist

Blueschist

Greenschist

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1 Formation

1.1 Formation

Blueschist forms due to the metamorphism of basalt and other rocks with similar composition at high pressures and low temperatures and approximately corresponding to a depth of 15 to 30 kilometers and 200 to 500 °C.

Greenschist is medium grade metamorphic rock, formed by the metamorphosis of mudstone or shale, or some types of igneous rock, when it is subjected to higher temperatures and pressures.

1.2 Composition

1.2.1 Mineral Content

Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, Quartz

Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Serpentine, Sillimanite, Staurolite, Talc

1.2.2 Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

CaO, Carbon Dioxide, MgO

1.3 Transformation

1.3.1 Metamorphism

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97% Igneous Rocks Rocks have it !

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50% Metamorphic Rocks Rocks have it !

1.3.2 Types of Metamorphism

Not Applicable

1.3.3 Weathering

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99% Igneous Rocks Rocks have it !

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65% Metamorphic Rocks Rocks have it !

1.3.4 Types of Weathering

Mechanical Weathering

Biological Weathering, Chemical Weathering

1.3.5 Erosion

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92% Igneous Rocks Rocks have it !

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77% Metamorphic Rocks Rocks have it !

1.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion

Blueschist and Greenschist Formation

Formation of rocks is a long process and hence, Blueschist and Greenschist formation sounds very interesting. According to the formation, all rocks are divided into :Igneous Rocks, Fossil Rocks and Metamorphic Rocks. Igneous rocks form by crystallization of magma or lava. The magma is made up of various components of pre-existing rocks which have been subjected to melting either at subduction zones or within the Earth's mantle. Igneous rocks are generally seen at mid ocean ridges or in intra-plate hotspots. Sedimentary rocks are formed when sediments accumulate gradually. As the sediments are buried they get compacted as more and more material is deposited on top. Eventually the sediments become so dense that they form a rock. Metamorphic rocks are rocks which once existed as igneous or sedimentary rocks but have been subjected to varying degrees of pressure and heat within the Earth's crust. Get to know all about formation of Blueschist and Greenschist, composition of Blueschist and Greenschist and their transformation.